113. Development, Optimization and Characterization of 3-mm Diameter Robotic Instruments for Robotic Assisted Cleft Palate Repair

PURPOSE: Cleft palate surgery involves dissection of delicate tissue within the confines of the infant oral cavity with reduced visualization, access and manipulability of standard instruments. Robotic assisted cleft palate repair uses dexterous tools and an endoscope that may improve precision. We have developed 3 mm diameter robotic tools that are optimized for cleft palate repair. This study investigates the performance of these tools using a high-fidelity cleft palate simulator test bed. METHODS: The 3 mm robotic instruments comprise of a wristed tool tip that couples to a da Vinci Research Kit (dVRK). The dVRK comprises two instrument arms with trocars and an endoscope for visualization. A virtual simulation was performed in MATLAB to determine the number of collisions (tool-tool and tool-oral cavity) based on the position along the palate and the height of the robotic arms (distance from trocar to oral aperture). Two experiments were performed using the 3 mm tools: (1) a MATLAB simulation validation involving suturing the cleft palate simulator oral mucosa at an anterior, middle and posterior position along the palate at three trocar heights and (2) a robotic assisted cleft palate repair on a high-fidelity cleft palate simulator. Both experiments were video recorded. The impact of tool position along the palate and the height of the robotic arms on collisions was determined for both experiments. RESULTS: The MATLAB simulation demonstrated increased collisions anteriorly and posteriorly with fewer collisions along the middle of the palate. The number of collisions increased with increasing trocar distance. The MATLAB simulation demonstrated a trend of increasing collisions anteriorly and posteriorly along the palate and increased collisions as the robotic arm trocar distance from the oral cavity increased (R2 = 0.9991, p = 0.0187). A robotic assisted cleft palate repair was successfully performed on the cleft palate simulator using the 3 mm tools. Lateral relaxing incisions, release of the velar muscles from the posterior hard palate shelf, suturing of the nasal mucosa, muscles and oral mucosa was successfully performed. Overall, collisions increased from anterior to posterior along the palate (mean increases of: 1.2 collisions/throw for nasal mucosal closure, R2 = 0.374, p = 0.005; 4.3 collisions/throw for oral mucosal closure, R2 = 0.407, p = 0.065) during the simulated cleft palate repair. CONCLUSION: A simulated robotic-assisted cleft palate repair was successfully performed using novel 3 mm diameter robotic tools. The tools were successful in executing the critical steps of a cleft palate repair. Instrument collisions were more frequent posteriorly and with increasing trocar height. Robotic assisted cleft palate repair using the 3 mm tools takes advantage of the robot’s superior visualization and dexterity and may improve the precision of cleft palate repair.